In the history of making beverages (e.g. beer, wine, etc.) involving fermentation, many techniques have been used to improve the quality of the resulting product with respect to flavor and appearance. With the use of mass production techniques, additional concerns arise such as shelf life of the resulting product and product throughput in the manufacturing facility. Similar concerns often arise with respect to other beverages derived from fruit (e.g. apple juice).
Chill haze is often a major problem that occurs in these various beverages. Chill haze is caused by certain proteins and polyphenolic compounds which are present in the beverage. With the time delay between manufacture and consumption of mass produced beverages and the consumption of beverages in a chilled state, the development of turbidity or chill haze is exacerbated.
To avoid chill haze problems in the resulting product, beverages are typically treated (chillproofed) to remove at least a portion of the proteins and polyphenolic compounds responsible for the problem. Unfortunately, it is often difficult to remove the problematic proteins without removing other constituents which are responsible for favorable properties (e.g. flavor, foam retention, etc.) Chillproofing is made more difficult by the desire (and often the need) to avoid addition of chemicals to the beverage. Food purity law and general health concerns may arise whenever auxiliary chemicals are used in beverage manufacture.
Tannins are known chillproofing agents for beer. In some instances, tannin has been used to influence the flavor of the resulting beverage (e.g., in the making of various wines). Tannin interacts very effectively with the proteins responsible for chill haze to create a voluminous precipitate which is then removed from the beverage by filtration or decantation. Unfortunately, removal of the formed precipitate is often difficult, requiring long settling time or very slow filtration. The presence of residual tannins in the beverage may have undesired effects on the beverage flavor.
Porous adsorbents such as silica gels have also been widely used for chillproofing whereby the proteins are adsorbed and removed from the beverage by filtration or decantation. While many silicas provide adequate chillproofing performance, there is a desire to achieve better performance, especially for high volume throughput brewery operations. Typically, silicas do not chillproof as well as tannins, but they are more easily removed from the beverage by filtration compared to tannin.
Some attempts have been made in the prior art to immobilize tannin on support particles such as silica particles by use of chemical bonding agents. In U.S. Pat. No. 4,500,554, tannic acid derivatives were immobilized on a treated silica support using chemicals such as aminopropyltriethoxysilanes and sodium periodate or formaldehyde. Unfortunately, such chemical immobilization has disadvantages in that the immobilization process is expensive and that the added chemicals may present food purity issues. Techniques using formaldehyde are generally ineffective for immobilization of the type of tannin most preferred for use in beer chillproofing.
Thus, there is a need for tannin-containing compositions that do not possess the filtration problems of conventional tannins nor the problems of known immobilized tannins.